<template>
	<div>
		<!-- 顶部滑动条区域 -->
		<div id="slider" class="mui-slider">
			<div id="sliderSegmentedControl" class="mui-scroll-wrapper mui-slider-indicator mui-segmented-control mui-segmented-control-inverted">
				<div class="mui-scroll">
					<a :class="['mui-control-item', item.id === 0 ? 'mui-active':'']" v-for="item in cates" :key="item.id" @tap="getPhotoListByCateId(item.id)">
						{{ item.title }}
					</a>
				</div>
			</div>
		</div>
	
		<!-- 图片列表区域 -->
		<ul class="photo-list">
			<router-link v-for="item in list" :key="item.id" 
			:to="'/home/photoinfo' + item.id" tag="li">
				<img v-lazy="item.img_url" />
				<div class="desc">
					<h1 class="desc-title">{{ item.title }}</h1>
					<div class="desc-body">{{ item.zhaiyao }}</div>
				</div>
			</router-link>
		</ul>
	</div>
	
</template>

<script>
	// 导入mui的js文件并初始化  做顶部滚动效果
	import mui from '../../lib/mui/js/mui.min.js'
	
	export default{
		data(){
			return {
				cates: [],   // 所有分类的列表数组
				list: []   // 图片列表的数组
			}
		},
		created(){
			this.getAllCategory();
			this.getPhotoListByCateId(0);
		},
		mounted() {  // 当组件中的DOM结构被渲染好并放到页面中后，会执行这个钩子函数
			// 如果要操作元素了，最好在mounted里面，因为这时候的DOM元素是最新的
			mui('.mui-scroll-wrapper').scroll({
				 deceleration: 0.0005  // flick 减速系数，系数越大，滚动速度越慢，滚动距离越小，默认值0.0006
			})
		},
		methods:{
			getAllCategory(){
				// 获取所有的图片分类
				this.$http.get('api/getimgcategory').then(result => {
					if(result.body.status === 0) {
						result.body.message.unshift({
							title: '全部',
							id: 0
						})
						this.cates = result.body.message;
					}
				})
			},
			getPhotoListByCateId(cateId){
				// 根据分类Id，获取图片列表
				this.$http.get('api/getimages/' + cateId).then(result => {
					if(result.body.status === 0) {
						this.list = result.body.message
					}
				})
			}
		}
	}
</script>

<style lang="scss" scoped>
	*{
		touch-action: pan-y;
	}
	li{
		background-color: #ccc;
		text-align: center;
		margin-bottom: 10px;
		box-shadow: 0 0 9px #999;
		position: relative;
		.desc{
			color: white;
			text-align: left;
			position: absolute;
			bottom: 0;
			background-color: rgba(0, 0, 0, .4);
			max-height: 84px;
			.desc-title{
				font-size: 14px;
			}
			.desc-body{
				font-size: 13px;
			}
		}
	}
	img[lazy="loading"] {
		width: 40px;
		height: 300px;
		margin: auto;
	}
	img{
		width: 100%;
		vertical-align: middle;
	}
	ul{
		list-style: none;
		margin: 0;
		padding: 10px;
		padding-bottom: 0;
	}
</style>
